New issue 574: Array index error in light ray generator https://bitbucket.org/yt_analysis/yt/issue/574/array-index-error-in-light-ra... Britton Smith: Occasionally, there is an array index error in the light rays during the step where the cells with zero path length are being removed around line 408 of light_ray.py. This appears to be because the dictionary holding all of the field data has multiple entries for a few fields, so they get altered more than once. Responsible: brittonsmith